Plastic particles can not form, have impurities, the 10 reasons and solutions are all here!#pelletizing recycling machine#recycling granulator machine#pelletizing equipment

In the process of producing engineering plastic particles,  we have a certain probability of encountering irregular particle shapes and impurities. Here, we will give you a brief talk about the causes and solutions of these situations.

1. Bar: 2 times longer than the normal grain

Reasons:

There are mainly boot pull or broken strip, the direction of the strip is not straight, the strip is not suitable, the grain cutter wear or gap.

Countermeasure:

● Adjust the direction of the material strip into the grain cutter and adjust the immersion length during normal production;

● The extrusion process needs to be adjusted for the broken bar during production;

● Pay attention to the inspection of the grain cutter, and replace the damaged moving knife in time;

● Suitable vibrating screen screen can be used for the long strip.

2. Link particles: two or more particles side by side together is called linked particles

Reasons:

The main driving strip is not timely split or broken strip, the immersion length is not enough, the nose temperature is too high.

Countermeasure:

● When extruding the pull strip, select the guide nylon wheel with the right width, and separate the material strips together in time;

● Adjust the appropriate cooling water immersion length, to prevent the overheating of the material strip, can reduce the granulation;

● Reduce the nose temperature appropriately and adjust the temperature of the material bar;

● For the occurrence, suitable vibration screen can be used.

3. Centipede strip: two or more materials are not all cut, together called centipede strip

Reasons:

The speed of the drive is fast and slow, the double screw extruder outlet, the immersion length is not enough, the grain cutter tool wear, or the gap between the knife and the knife is too large.

Countermeasure:

● The operator should pull the strip at a uniform speed to avoid too coarse material strip;

● Adjust the appropriate extrusion process to avoid discharging materials at the cutting outlet;

● Adjust the appropriate cooling water immersion length to avoid the strip overheating;

● Adjust the gap between the fixed knife and the moving knife, and then replace the new tool.

4. Black dots: Black spotted particles exist on or inside the particles

Main reasons:

Black spots in raw materials; screw carbonization; environmental pollution; artificial introduction.

Countermeasure:

● Strengthen incoming inspection, especially in filling mineral powder or flame retardant; these can not be used to produce strictly modified plastics

● Control the cylinder temperature and material residence time in the cylinder;

● Pay attention to the surrounding environmental hygiene and keep the ground wet, do a good job of isolation between the production of different colors of products;

● Clean up the auxiliary work of the extrusion equipment regularly;

● Every time the network, it is necessary to clean up the residual material on the mobile network board and template to prevent too long carbonization;

● Pay attention to the floor material strip is strictly prohibited to enter the grain cutter, to prevent the dust;

5. Discoloration: the performance for the production process of the product color suddenly change, appear obvious color difference

Cause:

Uneven mixing or incorrect mixing; the cleaner is not clean; the temperature is too high; the shear is too strong; the back admixture has miscellaneous particles.

Countermeasure:

● Strictly follow the mixing process to ensure the mixing uniformity and correctness;

● After the cleaning, special personnel to ensure that it is clean;

● Control the extrusion temperature to prevent the toner decomposition caused by too high temperature;

● Choose the appropriate screw combination to avoid too strong shear;

● Determine that the back admixture has no heterocles.

6. Vacuum defective material: two or more vacuum eyes or foaming phenomenon

Reasons:

Insufficient vacuum degree, vacuum return material, bad vacuum system, poor sealing, etc.

Countermeasure:

● Check and maintain the vacuum pump and the vacuum pressure gauge regularly;

● Clean up the vacuum tank, vacuum chamber and vacuum pipe in time;

● Appropriately control the flow of circulating water of the vacuum pump;

● Solve the vacuum return to ensure the vacuum cover is sealed.

7. Iron chips or other metal particles: iron scraps or other metal particles on the surface or middle of plastic particles

Causes:

Screw wear, broken breaking, iron scraps or other metal particles in raw materials.

Countermeasure:

● Check whether the screw, moving blade and vibrating screen are damaged;

● Check whether there are any corresponding metal particles in the raw materials;

● For bad products, strong magnetic or other metal separator can be used to screen out the metal particles;

● Add the filter screen for non-enhanced vehicles.

8. Poor plasticizing: from the particle cut surface to see refractory matter, or surface hair black phenomenon

Causes:

Heating temperature is too low, raw materials have impurities, feeding speed is too large, screw shear is too weak, too much lubricant in the formula.

Countermeasure:

● Control the temperature according to the process regulations, and adjust the temperature appropriately when bad plasticizing is found;

● Check whether there are any impurities or insoluble substances in the raw materials or in the process;

● Appropriately control the feeding speed, so that the plastic in the screw heating and plasticizing time growth;

● Select the screw combination with moderate shear ability;

● Adjust the formula appropriately.

9. High moisture: from the surface of the shiny water, or feel the material tide, or cut under the water and other similar phenomena

Causes:

The material strip is soaked too much, it is not divided in time when driving, the speed of the grain cutter is too fast, the wind knife is too small, and the distance between the grain cutter and the wind knife is too close.

Countermeasure:

● Adjust the length of the strip;

● When pulling the strip, the strip immediately after entering the grain cutter;

● Adjust the speed of the cutter appropriately, and the height of the rod bracket;

● Ensure that the wind knife is strong enough, and use two typhoon knives when necessary;

● Adjust the distance between the grain cutter and the wind blade appropriately.

10. Terminal material strip: after grain cutter, many tiny minced particles are produced

Causes:

Plastic static reasons, they adsorb in the vibrating sieve under the end of the main reasons for the material strip soaked in water too much, grain cutter wear, packing too much material too hard.

Countermeasure:

● Adjust the immersion volume of the material strip appropriately;

● Replace the new grain cutting tool;

● Adjust the formula appropriately to reduce the distance between the grain cutter and the wind knife.